The earliest attempts to detect poisons probably entailed animal and human tasters. Nero was able to poison Britannicus by putting arsenic in water which Britannicus used to cool the hot soup which passed his taster's test. The miner's canary long has been used to identify methane gas in mines. Color tests using treated filter paper, impregnated gels and bubblers are useful for many chemicals but have limited utility when looking for biological species or small trace markers for explosives. Likewise for battery powered “monitors” for explosive gas, phosgene and oxygen which have comparatively high lower limits of detection.
U.S. Published Patent Application 2003/0085348 A1 illustrates the difficulties in securing areas. The apparatus includes a room, an air handling system, an ion mobility spectrometer, a surface acoustic wave (SAW) device and ultraviolet fluorescence spectrometer, a Raman spectrometer, a DNA “sensor” with in-situ PCA amplification capability, microIR laser induced visible light, fluoroscope, a flow cytometer having a dye-containing binding agent-covered capsule with reporter bead chemistry and a metal detector. The apparatus requires the presence of an operator.
Cantion A/S is owner of published international applications WO 03104784, WO 03071258, WO 03067248, WO 03062135, WO 03044530, WO 2004059306 and U.S. Pat. No. 6,575,020 which are directed to systems for detection of bio-components in liquid using coated cantilevers with reference cantilevers and in arrays with specific binding partners.
A continuing need exists for simple, reliable and inexpensive detectors for toxic chemicals and biological agents.